Israel kept up its deadly bombardment of war-torn Gaza on Tuesday as Washington vetoed a U.N. Security Council resolution that called for a cease-fire in the Palestinian territory, where concern mounted about a growing humanitarian crisis.

Global powers trying to navigate a way out of the spiraling crisis have come up short, with a so-far fruitless push by mediators to reach a truce and two rival cease-fire proposals put forward at the United Nations.

Washington on Tuesday vetoed the first proposal, drafted by Algeria, which demanded an immediate humanitarian cease-fire and "unconditional" release of all hostages kidnapped in the Oct. 7 attacks.

Linda Thomas-Greenfield, Washington's ambassador to the U.N., called the vote "wishful and irresponsible."

Hamas said the U.S. veto equaled "a green light for the occupation to commit more massacres."

The veto provoked criticism from countries including China, Russia, Saudi Arabia, and even close U.S. allies including France and Slovenia.

With President Joe Biden facing increasing pressure to dial down support for Israel, Washington also put forward an alternative draft resolution on Gaza, giving support for "a temporary cease-fire in Gaza as soon as practicable."

As diplomatic powers wrangled, Israel hit Gaza with air and ground assaults that killed a total of 103 Palestinians in the past 24 hours, its health ministry said.

The ministry said Israeli strikes continued into Tuesday night, with one killing at least 15 people at a house in central Gaza's Deir al-Balah. The southernmost city of Rafah was also bombed.

The U.N. has repeatedly sounded alarm over Gaza's dire humanitarian situation and warned food shortages could lead to an "explosion" of preventable child deaths.

Despite having only just restarted much-needed deliveries into the hard-hit north, the U.N.'s food program said Tuesday it had been forced to stop after facing "complete chaos and violence."

The World Food Programme resumed deliveries Sunday but its convoy was met with gunfire, violence, looting, people trying to climb onto the vans, and a truck driver was beaten, it said Tuesday.

The WFP acknowledged that halting deliveries meant the situation "will deteriorate further and more people risk dying of hunger."

More than four months of relentless fighting have flattened much of the coastal territory, pushed 2.2 million people to the brink of famine and displaced three-quarters of the population, according to U.N. estimates.

"How many of us have to die ... to stop these crimes?" said Ahmad Moghrabi, a Palestinian doctor in southern Gaza's main city, Khan Yunis.

Some 1.4 million Palestinians are now sheltering in Rafah, many living in makeshift tents.

The overcrowded city — the last untouched by Israeli ground troops — is also the main entry point for desperately needed relief supplies via neighboring Egypt.

Despite international pressure, Israel has insisted that a ground operation in the city is essential to destroy Hamas.

Leaders of global humanitarian groups said Tuesday that an offensive in Rafah could turn the city into a "graveyard," warning the consequences of a full-scale assault are "truly unimaginable."

Israel has said that unless all Israeli hostages are freed by the start of Ramadan on March 10 or 11, it will push on with its offensive during the Muslim holy month, including in Rafah.

The war started when Hamas launched its unprecedented attack on Oct. 7 that resulted in the deaths of about 1,160 people in Israel, mostly civilians, according to an AFP tally of Israeli figures.

Hamas militants also took about 250 hostages, 130 of whom remain in Gaza, including 30 presumed dead, according to Israel.

Israel's retaliatory campaign has killed at least 29,195 people, mostly women and children, according to the latest count by the territory's health ministry.

For weeks, Israel has concentrated its military operations in Khan Yunis, the hometown of Hamas's leader in the territory Yahya Sinwar, the alleged architect of the Oct. 7 attack.

The army said Tuesday troops were continuing "intensive operations" in the city and "killed dozens of terrorists over the past day."

Witnesses said Gaza City's southern Zeitun neighborhood had also come under heavy bombardment.

"We don't know where to go — every place is being bombed," said resident Abdullah Al-Qadi, 67.